Overhead tractor



April 18, v1939. A.D;sAEfcM-fsm! l K 2,154,702

OVERHEAD TRACTOR Filed Sept. 24, 1934 2 Sheets-Sheet l INVENTOR. -H RTHwg D. Sa'aonsxy.

6 I SY iufm@ j ATTORNEY;

April 18, 1939.

A. D. sABoRsKY 2,154,702

OVERHEAD TRACTOR Filed Sept. 24, 1934 r2 Sheets-Sheet 2 '39 Il) A35? 22' 532 u, l #lL- 33x aa'l l S ,1 l 41 32 4 Z0 m INVENTOR. 51 53 VIl'lvrhfuw D. Snacks/(y.

u 35. J4 BY l LA OM ATTORNEY.

Patented Apr. 18, 1939 UNITED STATES wirr-:NTl OFFICE Arthur? Ohio s claims. '(ol. 10s-15s) This invention relates to a.V motordriven tracy tor, load carrier or lhoist mechanism of the type that travels on an overhead material handling system. The embodiment herein disclosed is i1- lustr'ated for engagement 4with and suspension from a steel rail (ordinarily termed a monorail or tramral), shownsubstantially T-shaped in cross section, providing trackage forl one or more wheelsf or one or more pairs of wheels and a traction surface for a driven traction wheel.

In the construction 'of `devices of this character, of which I have knowledge, it has been the practice to interpose between the traction wheel and the supporting wheels a spring or springs, whereby the traction wheel was maintained in yielding engagement with the rail to insure traction eiiort or effect. This involved extra parts and increased the size of the mechanism. Also, in I such arrangement and with solid metal traction wheels, the curved portions of the rail had to be curved about a relatively longradius to prevent the tread oi the traction wheel from disengaging the rail when negotiating curved portions thereof,

and further to prevent excessive lateral frictional i rxestance between the traction wheel and' the One object of the invention is to provide an improved overhead load propelling device of this character of simple construction adapted to insure adequate traction with a supporting rail in a simplified manner, lwhereby positive and emcient driving eiect results.

Another object of the invention is to provide an improved device of this character of simple construction adapted to insure adequate traction between the driven traction wheel and a supporting rail in a simplified manner and topermit the rails to be curved on a relatively small radius to meet varying conditions in propelling various loads along the rail.` y

Another object of the inventionis to provide an improved device ofthischaracter having a driven resilient traction wheel arranged to ilex I laterally to accommodate itself to curvalinear portions or the rail, whereby slippage, and waste of power or current are substantially reduced.

Other objects of the invention will be apparent to those skilled in the art to which myinvention relates from the following description'taken in 0 vconnection with the accompanying drawings,

@wherein l. Fig. 1 is a view (partly in elevation and partly 'in section) of a device embodying my invention, the device being shown supported by and suspended from a Fig. 2 is a section onv the line 2l-.2 of Fig. 1. Fig. 3 is a plan view shcwingfthe device negotiating a curved portion-of the rail.

Fig. 4 is a fragmentary section on the line 4--4 of Fig. 3. '5

y Fig. 5 is an elevational view showing a diierent embodiment of the invention. l Fig. 6 is a section on the line 6`-`6. o'f Fig. 5. Fig.- 'I isa fragmentaryl section substantially similar to Fig. 2,' but illustrating another modiii- 10' cation. j

My invention herein disclosed may be embodied in a motor driven tractor,A load carrier or hoist as used in the overhead material handlingA industry,

but for illustrative'purposes I have shown it apy plied to `or embodied in a tractor`, as being the preferred application lof 'the invention; accordingly, the 'termtractor or device herein used is for the purpose of description and not for purposes of limitation. f Y In the drawings, I indicates the rail suitably supported by spaced hangers 2, only one being shown (see 1).`A I vindicates as an entirety the main frame of the tractor comprising oppositely` related'irame sections 4, 5,l forminga g5 housing and` shaped to form between them, at their upper ends,v an opening 6 for a purpose later set forth. The sections 4, 5, are of general curvalinear' shape, the side' and lowerv edges thereof being provided with outwardly extending anges y30 1 which are secured together by bolts or .cap screws I. Each section 4, E, is formed in its side wall with-an opening! alined with theopening 9 in the otherseotion. The wall of each section forming the Vopening 9Y therein extends laterally 35 outwardly,v to provideadequate space within the housing, and such w'all is provided at its'outer end withl arrinturned peripheral flange I0, the

I2, the heads of the pins restingon the upper 45" edges of the arms I I. The lower endsoithe pins extend through the central portions ofinv'erted U-shaped wheel supporting frames I3 to permit the latter toswivel. The free ends' of the wheel frames Il `are provided'with.' inwardly extending 50 shafts 'Ila on which are suitably mounted kwheels I4 arranged to engage and run on the rrail I, as shown.`As will'be.understood.the wheels I4 movably support the frame 3 on the rail I, the pivot'pins l2 permitting the frames I3 to swivel 5g 4 from the free edge of the adjacent ange Il.

when the wheels I4 traverse or negotiate curved portions of the rail I as show'n in Fig. 3. 'I'he outer ends of the arms Il carry suitable devices I5, such as loopshaped members. which serve as bumpers and also as coupling elements,to be connected to a load carrier (not shown).

I3 indicates an electric motor. 'Ihe housing of the motor adjacent its inner end is provided with a flange I1 which is rigidly secured by bolts to the angeil 4of the frame section l. The inner end of the motor casing is provided with an inwardly extending collar I3 which forms'the seat for the outer race of an anti-friction bearindicates an anti-friction' bearing carried by the frame section 4 and axially related tothe bearing I9. The outer race of the bearing Il' is mounted ina seat provided by a collar Ila extending inwardly from. and spaced The purpose of the bearings Il, Il', will later appear. The shaft 2li ofthe motor I3 extends through the openings- 9 formed in the sections 4, I, the outer end of the shaft being mounted in an antlfrictionbearing -2I-vfmounted on the end wall of av casing 22. 'I'he inner end of the casing is open and provided with a flange 23 which is suitably secured to the flange I0 on the frame section 4. The motor shaft 20 is provided with a'pinion 24 which transmits the power of the motor Il through a suitable reduction gearing 25, within the casing 22 to drive a hollow shaft 23, to be later referred to, mounted in the bearings I3, Il', the shaft 20 being made hollow to accommodate the motor shaft 2l, as shown.

'I'he reduction gearing 25 may be of any desired construction, butpreferably comprises the following: 21 indicates a shaft mounted in and extending through a suitable bearing provided on the side of the casing 22 therewithin. The outer end of the shaft 21 carries a gear 2l in mesh with the pinion 24. The inner end of the shaft 21 carries a pinion 2l in mesh with a gear Il which is splined or keyed to the adjacent end of the. shaft 23. The casing 22 is of sectional construction for assembly and disassembly purposes.

3| indicates as an entirety a traction wheel which is driven by the shaft'2l and extends, at its upper portion, through the opening 6 between the frame sections 4, t, for engagement with the rail I. The traction wheel 3| comprises an inner or web section 32, preferably formed integrally with the shaft 26, and a resilient or yieldable annular section 33, which preferably forms the outer section of the wheel and accordingly normallyl resiliently or yieldingly engages the traction surface of the rail I. The wheel section 33 is shown as consisting of an annulus formed of rubber or rubber compound, which permits it to be compressed and also flexed, whereby it engages yieldingly and underpressure the rail I and its portions outwardly of the wheel'section 32 may readily yield or flex laterally in either direction, for example, while ybeing driven sothat its rail engaging surface will remain intraction engagement with the rail as the tractor negotiates -curved portions'thereof. 'I'he rubber section 33 is fixed to the inner wheel section 32 to rotate therewith and yresiliently engages the rail Ito insure effective traction therewith when driven. As shown, 4the shaft 23 is so mounted on thegframe 3 with respect to the rail I, that the resilient section 33 of the wheel 3l is compressed at or along that Portion vwhich is in engagement with the rail I and hence is always under pressure engagement therewith.

mismos 'Ihe rubber section 33 snugly but removably, iits the peripheral side wall of the section 32 against a circumferential flange 34 on one edge thereof and is secured against the flange by a removable ring 3l. In the event the rubber section 33 wears away or greater pressure engagement with the rail I is found desirable, it may be removed and a new one substituted. While the rubber section 33 is shown of substantially rectangular cross section', it may be otherwise constructed to secure any'desired resiliency; for exampie,'it may be made hollow or formed with transverse openings ,throughout its circumference or it may be formed in sections. The ring 35 is removably held in position by suitable bolts threaded into the web section 32.

My construction of traction wheel is advani rail, this axis being preferably spaced below the rail a distance less than the normal radius of the wheel and tire, so that the latter will be flattened or distorted as shown in Figs. 1, 2 and 6 to form an enlarged area of contact with the under side of the rail when the wheel and rail are in assembled position and insure adequate f-zictional contact of the tire with' the rail. Accordingly, springs are not required to effect yielding or pressure engagement of the wheel with the rail. Furthermore. when the tractor traverses curved portions of the rail I, as shown in Fig. 3, the resiliency of the rubber section permits its outer circumferential portion to flex laterally, as shown in Fig. 4, so that its peripheral wail, due to its frictional engagement with the rail, remains in engagement therewith without undue lateral sliding on the rail. Accordingly, tractivev effort is continuously maintained throughout the vcurved portions of the rail without undue loss of power or waste ofl current. Due to this characteristic advantage. the rail may be curved on smaller radii, where such conditions are found desirable, without danlger of the traction wheel disengaging the rail, the result of which would stall the tractor and/or permit 4racing of the motor.

33 indicates a box containing suitable electrical controls for lthe motor I6 and mounted in a well-known manner on the outer wall of the sec. tion 4. 31 indicates a conduit depending from the box 33v and enclosing leads connected to the contacts of a push button switch 33 at the lower end of the conduit 31.

Figs. 5 and 6 show an embodiment of the invntion in which the axis of the traction wheel extends in a vertical plane cutting the axes of one pair of supporting wheels. In this arrange-v ment, the shafts for one pair of supporting wheels may be relatively stationary and the removablev resilient section of the traction wheel may be reduced radially, if desired (as shown). Re-

ferring to these figures, 4, l', indicate the frame vsections which are substantially similar to the sections already referred to except that they are shaped 'to provide (a) integral up-standing arms or hangers 39 and (b) integral depending members 4l. 'Ihe arms support shafts I 3 for one pair of supporting wheels I4'. The depending members 4l are arranged side by side and formed on their opposed faces with semi-circular recesses to provide a bearing for a swivel pin 4l. The pinA 4i extends through the bearing and the hollow boss 42 on the adjacent end of a tail member 43. The 'upper end of the pin 4I is provided with a head 4i' which engages the members 40 to support the pin in position; its lower end is provided with a suitable device, such as a cotter pin 44, preferably engaging a washer, to hold the tail member 43.0n the pin and connect it to the sections 4', 5'. The opposite end of the tail member 43 is provided with an opening 45 through which a pivot pin 4i extends, the pin also extending through the central portion of a substantially -U-shaped wheel supporting frame 41 to permit the latter to swivel on the pin. The pin 4i is provided with a head which engages the upper face of the tail member to support the pin in the opening 45; its lower end is provided with a suitable device, such asa cotter pin 48, preferably engaging a washentohold the frame 41 to the tail member 43. The arms of the member 41,v at their free ends, are provided with inwardly extending shafts 49 which support a pair of supporting wheels |43, The arms of the member 41 are provided with outwardly extending flugs 60 to which is fixed a bracket 5|. The bracket 5I supports a pair of depending shafts 53 for rollers 54'V which engage the opposite lateral sides of the rail I, as shown. l2 indicates a coupling element preferably provided on the Vrear end of the tail .j

member 43. likewise, each frame section 4', 5', is formed with recesses 55 in which 4are suitably mounted shafts .5l carrying rollers 51 arranged to engage the opposite laterairsides of the rail i as shown.

The construction and mounting of the, motor I8', casing 22', reduction gearing 25', shaft 26 and traction wheel 3|' are similar to like parts shown in Figs. 1, 2, 3 and "4, except that the resilient section 33' need not be so constructed as to `provide lateral exibility, this construction being permissible as the traction wheel engages the rail at the same point as the adjacent pair of supporting wheels I4' and turns therewith as the tractor traverses curved portions of the rali.

Fig. 'l illustrates a construction wherein the tire, indicated at 33a' is of hollow form and surrounds the wheel section I2 so as to frictionally engage the rail I.

From the foregoing description it will be noted vum che frame is provided with wheels having axles which are non-yieldably supported and engage opposite portions of the-rail. While certain of the wheels may, as shown in Figs. 1, 2

and 3, be mounted to swivel, whether `they are so mounted or not, the axes of all the wheels have a relatively xed relation to the frame; on the other hand one wheel (namely, the traction wheel in the disclosed embodiment) has a yieldingcircumferential portion, which is shown as engaging the rail, serving to eect pressure engagement of all the wheels with the rail.

To those skilled in the art to which my invention relates, many changes in construction and.

widely differing embodiments and applications of the invention will suggest themselves without departing from the spirit and scope of the invention. My disclosures and the description herein are purely illustrative and not intended to be in any sense limiting.

What I claim is:

1. In combination, a tramrail.` an overhead tractor for propelling variable loads kalong said tramrail and provided with supporting wheels and arranged to run on top of the tramrail flanges, a traction wheel engaging the bottom `side said tramrail iianges, said traction wheel having a non-metallic circumferential portion formed of resilient material permitting radial flexing thereof to exert pressure against the tramrail flanges and shaped in cross section to provide for lateral iiexing `as said wheel negotiates curved portions of said tramrail, the traction wheel and supporting wheels being mounted on said tractor in xed relationl to each other, whereby to maintain `constant pressure on said tramrail between the said supporting wheels and the said traction wheel.

2'. A traction device for moving variable loads along an overhead carrier system having a supporting rail, said device including a trolley having supporting wheels to run on a supporting rail of such a. system, a rigid frame carried by said trolley, a traction wheel carried by the frame and having an axis maintained a xed predetermined distance from the axes of the supporting wheels, said wheel having a periphery formed of 4deformable resilient material to engage fricporting wheels that the wheel periphery, when said device is assembled, will exert pressure against said fixed part of the system and thereby deform said wheel periphery, and means 'for driving the traction wheel and thereby moving variable loads along the system.

3.` A traction device for moving variable loads along an overhead carrier system having a supporting rail, said device including a trolley having supporting wheels to run on a supporting rail of sucha system, a rigid frame carried by said trolley, a wheel carried by the frame and engaging theunderide of said rail, and having an axis maintained a fixed predetermined distance from the axes of the supportingv wheels, means for driving one of said wheels and thereby moving variable loads along the system, said driven wheel having a deformable tire formed of resilient material, whereby, when the device is assembled the peripheral portion of said tire is deformed at the point of contact with the rail to eilect frictional engagement therewith.

(i. Ina traction device for moving variable loads in an overhead carrier system, the combination with a supporting rail, of a trolley comprising a-frame having spaced supporting wheels arranged to run on said supporting rail, a traction wheel carried by said frame and having a solid tire formed of resilient material arranged to frictionally engage with the under side of said rail and to iiex laterallyv in either direction while negotiating curved portions of said rail, said traction wheel having its laxis maintained in a fixed predetermined position relative to the axes of said supporting wheels, the distance of the axis of said traction wheel from said rail being less thanthe normal radius of said tire, and means for driving said traction wheel and thereby moving variable loads along said rail.

5. In a traction device for moving variable loads in an overhead carrier system, the comthe vframe v'beneath said rail, a traction wheel Y negotiatingr curved portions of said rail, said ,traction wheel having its axis maintained in ay fixed predetermined position relative to .the axesv of said supporting wheels, the distance of the axis of said traction Wheel from said rail being less than the normal radius of said tire, and means for driving said traction wheel and therebymoving variable loads along said rail.

6. In a tractiondevice for an overhead carrier,v system, the combination with an` overhead rail,

of a frame,`tro1leysvat tached'to the frame and having supporting` wheels to` run onand support having a solid tire. formed of resilient material, the axis of said wheel being so positioned relative to the frame that/when the device is assembled with the rail, thel tire` will be. distorted by and,

will exert substantially uniform pressure against the under surface of therail throughoutsubstantiallydts entire width, the resiliency ofjsaid tire providing for flexing thereof laterally vin either direction in negotiating curved portions of said rail, and means connecting the fraxneand supporting wheels for preventing` changevertif cally betweenv the axis ,ofthe tractionwheel and the axes of said supporting wheels.

7. In a traction device for moving variable loads along an overhead carrier system, the combination with'a supporting rail, of a trolley having supporting wheels to run on 'said supporting A rail, a rigid frame carried by said trolley, a wheel carried. by the trame, and engaging the under a fixed predetermined distance from the axes of the supporting wheels, means for driving 'one of said wheels and thereby moving variable loads along, the system, `said. driven wheel having a vdeformable. tire of non-metallic material arranged to engage frictionally 'with said rail and to `iiex laterally when the said wheel is negotiating curved portionsof said rail.

8. A traction device for an overhead carrier system including a frame, trolleys attached tothe frameand having supporting wheels to run on and support the frame beneath an overhead rail,

a resilient, deformable tired'traction wheel having its axis so positioned relative to the 'frame Y that, when the device` is assembled with the rail,

the `-tire will be'distorted by, and will exert' sub- ,'stantially uniform pressure against the undersurface of the mi throughout substanuauy its entire width, and means connecting the frame f and the wheel for preventing change in position of the axis of the traction wheel relative to the rail when the device and rail are in assembled position.

ARTHUR D. sABoRsxY.

side of said rail,and having an axis maintained 

